CAT 535-8211 BUSHING-SEM

CAT 535-8211 is a Caterpillar genuine SEM (Structural Engineering Machinery) wear-resistant bushing, suitable for the boom, stick, or frame articulation parts of heavy equipment such as excavators and loaders. It is used to withstand heavy loads and impacts, reduce friction, and extend the life of pins and supports. The following are core original specifications and application information, excluding replacement parts (Cat®)…

Core Technical Parameters

Item Details
Part Model CAT 535-8211 (SEM BUSHING)

Product Type Heavy-duty equipment articulated bushing, suitable for high-frequency articulation parts such as booms, sticks, and frames, providing radial support and friction reduction.

Material Outer layer low-carbon steel (1010 steel) + inner layer copper-based alloy (CuPb24Sn4) bimetallic structure, alloy layer thickness 2.5 mm, tensile strength ≥300 MPa, hardness HB 180–220

Surface Treatment Lead-tin alloy plating on the inner hole (thickness 5–8 μm), excellent friction reduction and anti-galling properties; precision machining of the outer circle, surface roughness Ra ≤ 0.8 μm

Key Dimensions Inner diameter 50 mm, outer diameter 65 mm, total length 100 mm, chamfered ends 1×45°, suitable for standard pin assembly

Single Weight Approx. 0.92 kg (2.03 lbs)

Working Performance Operating Temperature -30℃ ~ +120℃, suitable for hydraulic oil and grease in engineering machinery. Relies on grease lubrication and requires regular replenishment.

Matching Requirements: Clearance fit between the inner bore and pin (clearance 0.030–0.050 mm); interference fit between the outer diameter and mounting hole (interference 0.020–0.030 mm).

Lubrication Design: Six axial oil reservoirs + circumferential oil channels distributed within the inner bore, suitable for centralized lubrication systems. Grease filling pressure 10–15 MPa.

Structure and Core Characteristics:
Bimetallic Composite Structure: The outer layer of low-carbon steel provides high strength and rigidity, while the inner copper-based alloy offers excellent friction reduction and embedding properties, compensating for minor installation errors between the pin and support, absorbing impact loads, and protecting the pin and mounting hole from wear.

Precision Lubrication Design: The inner bore oil reservoirs and channels ensure uniform grease distribution, reducing friction and wear at hinged joints, suitable for high-frequency oscillation conditions in heavy equipment, and extending maintenance intervals.

Installation Compatibility: The interference fit on the outer diameter ensures no looseness after bushing installation, while the clearance fit on the inner diameter facilitates pin rotation. The chamfered ends facilitate assembly and prevent scratching the pin surface.

Working Condition Compatibility: Suitable for harsh working conditions such as heavy loads, vibration, and high dust levels in construction machinery. It boasts excellent impact and fatigue resistance and a long service life.

Compatible Models and Application Scenarios

Compatible Equipment Models: CAT 320GC, 323GC, 326GC excavators, 950GC, 966GC loaders, and some SEM series construction machinery equipment.

Compatible Parts: High-frequency swinging parts such as the boom and stick hinge, stick and bucket hinge, and frame and boom hinge.

Core Application: Used for radial support and friction reduction at hinged parts, reducing friction and wear between the pin and support, ensuring flexible equipment operation, and preventing equipment failure due to hinge failure.